Utility knives for a variety of purposes have been around for many years. These knives typically include razor-sharp blades which permit clean, accurate cuts to be made in a variety of materials as desired. The typical utility knife consists of a handle which houses a replaceable blade. Thus, as the blade becomes dull from repeated use it can be replaced with a fresh blade without having to discard the entire knife.
Over the years it became apparent that generally only the tip of the blade was becoming worn, while the remainder of the cutting edge remained fairly sharp. Thus, blades were being discarded which, for the most part, still maintained an adequate cutting edge for substantially their entire length.
With this recognition came the advent of segmented knife blades. In these devices, the knife blade is divided into a plurality of segments by scored lines which traverse the blade at regular intervals along its length. By detaching a blade segment from the remainder of blade along one of these weakened segmentation lines, the worn tip of the blade may be discarded while simultaneously providing a new, sharp tip for the blade. Thus, by detaching individual blade segments from the blade the entire cutting edge of the blade is utilized in a more uniform fashion and the life of the blade is extended.
With currently available utility knives having segmented blades, it is necessary to extend those blade segments which one desires to detach from the remainder of the blade outside of the blade handle or housing. One may then grasp the extended blade segments and break them along a segmentation line from the remainder of the blade. Since the force required to break the blade segments from the remainder of the blade is rather severe, this procedure is not typically done by hand as it could easily result in injury. Therefore, a pair of pliers or similar instrument may be used to grasp the extended blade segments for breaking from the remainder of the blade. While these instruments may facilitate the breaking of the blade segments, they are nonetheless cumbersome to use and do not provide adequate safeguards from injury.
In many situations, pliers or other instruments are not available to detach the blade segments. Therefore, in order to facilitate this procedure, utility knives were developed in which the handle or housing includes a detachable device having a slot which may be assembled over the blade segments to provide grasping means for detaching the blade segments.
Even when these devices for grasping the blade segments are utilized, however, there is still a very real potential for injury. Thus, should the device not grasp the blade segments securely, the blade segments may be sent flying and result in injury as they are detached from the remainder of the blade. Furthermore, the force required to break the blade segments from the remainder of the blade may result in cuts to one's hand from either the detached blade segments or the portion of the blade which remains. Additionally, detachment of the blade segments may result in the formation of metal splinters which could easily cause injury. Still further, detaching the blade segments carelessly or in an improper manner may result in personal injury or damage to the handle or housing.
Thus, the need exists for a device which will enable the blade segments to be detached from a segmentable knife blade without exposure to the aforementioned hazards. There is also a need for such a device which can be readily incorporated into presently available utility knife designs.